Forced circulation gas water heater

ABSTRACT

A gas valve for the burner of a water heater is L-shaped with valves in each branch of the L. Push rods, positioned at right angles to each other, respectively operate the valves. One rod is actuated by an electromagnet and the other by a fluid pressure responsive diaphragm connected to a venturi. The venturi is in a water circuit that includes the heater, two temperature-limiting thermostats, a radiator and a circulating pump. An electrical circuit has two branches; one of which includes a switch controlled by one thermostat and the circulating pump motor; and the other of which includes switches controlled by both thermostats and the electromagnet.

Inventor ll-lhms Meier Remscheld, Germany Appi. No. 111,125 Filed Felt. 113, 1970 Patented Dec. M, R9711 Miiignee Joli. i/alllam KG Remsclteld, Germany Priority Well). M, W69

Germany P 19 Ml Mil-ii FORCED CIRCULATION GAS WATER lilllEA'llElli 4 Claims, 1 Drawing Fig.

[1.8. Ci 237m,

236/21, 236/25 Int. Cl lFZld 3/02 Field of Search 237/8 we, we

[56] References Cited UNlTED STATES PATENTS 3,383,042 5/1968 Mobusetal. 237/8 IFOIRElGN PATENTS 63l,432 8/1963 Belgium 237/8 Primary Examiner-lEdward J. Michael Altarney- Darbo. Robertson & Vandenburgh AliiS'llllkACT: A gas valve for the burner of a water heater is L shaped with valves in each branch of the L. Push rods, positioned at right angles to each other, respectively operate the valves. One rod is actuated by an electromagnet and the other by a fluid pressure responsive diaphragm connected to a venturi. The venturi is in a water circuit that includes the heater, two temperature-limiting thermostats, a radiator and a circulating pump. An electrical circuit has two branches; one of which includes a switch controlled by one thermostat and the circulating pump motor; and the other of which includes switches controlled by both thermostats and the electromag net.

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BACKGROUND AND SUMMARY OF THE lNVlENTllON The invention relates to a forced circulation gas water heater for operating a hot water heating system and comprising: a gas fitting in the gas path to the burner, which fitting has an L-shaped gas passage with a gas valve in each branch of the gas passage, each of which valves are a plate valve and are operated by a push rod, the push rods of the two gas valves being disposed in cruciform pattern relative to each other; a diaphragm-actuating member adapted to respond to the flow pressure in the circulating water path operatively associated with the push rod of one of said gas valves; a magnet whose armature is operatively associated with the push rod of the other gas valve; and a temperature-limiting control which can be actuated by a thermostat which responds to excess temperature.

A requirement for forced circulation gas water heaters is to have a gas safety valve, controlled by a temperature-limiting device, in addition to the gas valve which is controlled by the room thermostat and feed thermostat as well as by the flame monitor.

ln forced circulation water-heating systems with a then moelectric ignition safety device, the temperature-limiting switch is connected in the thermostat circuit so that the limiting switch interrupts the thermostat circuit in the event of excess temperature thus causing the ignition safety valve to close. However, an ignition safety valve of the hind heretofore described is not provided in apparatus having electronic flame monitoring for the burner. Accordingly, such apparatus requires an electrically controllable gas safety valve which is governed by the temperature-limiting device.

It has already been proposed for the temperaturedimiting device switch, taking the form of an electric switch which opens with rising temperature, to be connected in circuit of the circulating pump, which pump in turn governs a low water safety valve via a diaphragm-actuating member responding to the closing pressure in the water-circulating path.

The prior art also discloses a system in which a gas fitting with an L-shaped gas passage is. provided in the gas path to the burner. One gas valve each, constructed as plate valve, is provided in each branch of the L-shaped gas passage. The gas valve in the horizontal branch is the ignition safety valve which may be pushed open by means of a horizontally disposed push rod actuated by a manually operated pushbutton. A gas valve, which can be operated by an electromagnet via a vertically disposed push rod, is positioned in the vertical branch of the gas passage. The room thermostat and feed thermostat, as well as a switch contact operated by a diaphragmactuating element which responds to the flow pressure in the water circulation path is connected in the circuit of the electromagnet.

It is an object of the invention to provide a forced circulation gas water heater of the kind mentioned heretofore which is as simple as possible and to construct it from a minimum number of parts.

It is a further object of the invention to provide a forced circulation gas water heater in which the flame is monitored by an electronic flame monitor and in which a gas valve is provided which is controlled by the temperature'limiting device and is independent of the flame monitor.

According to the invention this is achieved in that the diaphragm-actuating element acts directly on the horizontally disposed valve push rod of the fitting and the temperature limiter is connected in the circuit of the water-circulating pump; the ionization apparatus (flame monitor) controls the circuit of the magnet controlling the actuation of the vertically disposed push rod of the gas valve operated by the magnet.

DESCRIPTION OF THE DRAWlNG The drawing illustrates diagrammatically a system embodying the invention with the electrical, but not the gas, circuit in "operating" position.

DESCltlPTllON 0F SlPlEClFlC EMIB'ODIMENT The following disclosure is offered for public dissemination in return for the grant of a patent. Although it is detailed to ensure adequacy and aid understanding, this is not intended to prejudice that purpose of a patent which is to cover each new inventive concept therein no mater [how others may later disguise it by variations in form or additions or further improvements. The claims at the end hereof are intended as the chief aid toward this purpose, as it is these that meet the requirement of pointing out the parts, improvements, or combinations in which the inventive concepts are found.

The water in a water circuit, generally l, is circulated by a pump 2 between a heat exchanger 5 and the radiators 3. The heated water flows from the heat exchanger through a feedline 6 and returns through a venturi d. In the feedline 6 are a temperature-limiting control thermostat 7 and a feed thermostat h.

Gas is supplied to burner Ml through a gas control indicated generally by reference number 116 through a supply socltet it) a. The gas control 116 is basically of lL-shape, comprising a horizontally disposed branch 10 and a vertically disposed branch 9. The horizontal branch contains a spring-loaded disc valve 1111 which also is urged in the closing direction by gas pressure. Valve M is controlled by a water-actuating device 12 one of whose diaphragm chambers is biased by the negative pressure in the venturi nozzle d. Diaphragm l2 actuates valve llll through a push rod 1111 a. The passage of the gas is also controlled by a gas valve 113 in the vertical branch 9 of the gas fitting 116 before it reaches the gas burner M. The gas burner is electronically monitored by a flame'sensing means 17 and electrically ignited, features which are ltnown and, in the interests of simplicity, the latter is not shown in the drawing. The gas valve 113 is operated by an electromagnet 15 through a push rod 13 a. The armature of the electromagnet is connected to a dashpot device so that the operation thereof is delayed.

An electrical circuit, generally llli, includes (starting from R/lvlp) a branch through only switch 7 to the motor of pump 2 and a second branch through switch '7', switch 8' and switch 117' controlling electromagnet l5. Through switch 7, the temperature-limiting device 7 controls the circulating pump 2 and the electromagnet 15. The feed thermostat h and the flamesensing means 17 only control the magnet 11$ through switches h and H7 respectively.

During heating operation and when the temperature preselected on the feed thermostat b is reached (cg. 185 F.), the switch 8 of the feed thermostat opens. This interrupts the circuit of the electromagnet so that the gas valve 13 closes by reason of the spring pressure thereon. The gas path is thereby blocked and the heating is interrupted until the circulating heating water is cooled to the switching-on temperature. If there is a fault in this control procedure so that heating is continued despite the fact that the preselected feed temperature was reached, the circuit of the switch 7' of the temperature-limiting device 7 and controlling the circulating pump 2 and the electromagnet 115, is opened when a preselected limiting temperature (e.g. 205 F.) is reached. The pump 2 is stopped and this results in response of the diaphragm-actuating device 12 so that the gas valve ill closes (low water safety valve) and also blocks the passage of gas to the gas burner. The flame-sensing means 117 opens switch 17 should the flame go out.

lclaim:

l. A hot water heating system including:

a water circuit having a heat exchanger, a radiator and a circulation pump;

a gas burner for supplying heat to said heat exchanger, said burner including a gas supply device having a fitting defining an L-shaped gas passage with a first gas valve in one branch of said passage and a second gas valve in the second branch of said passage, each valve including respective operating rods with the rods being positioned in a cruciform pattern relative to each other, fluid pressure responsive diaphragm-actuating means bearing directly on one rod for actuating one valve and operatively connected to said water circuit to be responsive to the operation of the pump, and electromagnet means operatively associated with the other rod for actuating the other valve to the open position;

an electrical control device having a thermostat and a first switch, said thermostat being positioned to be responsive to the temperature of the water in said circuit to actuate said switch in response to excess temperature;

flame-sensing means having a second switch and positioned to actuate said second switch depending upon the presence and absence of a flame at said burner;

electrical circuit means for said pump and said electromagnet means, said electrical circuit means including said first and second switches, said first switch being connected to deenergize said pump upon excess temperature in said water circuit and said second switch being connected to deenergize said electromagnet means upon the burner going out for allowing said other valve to then close.

2. A hot water heating system as set forth in claim 1,

wherein said two branches of said passage are at right angles to each other and the two valves are at right angles to each other, and the push rods are at right angles to their respective valves.

3. A hot water heating system as set forth in claim 2, wherein said one valve is normally biased in the closing direction of that valve and said fluid pressure responsive diaphragm-actuating means comprises:

a casing having ahollow interior;

a resilient diaphragm dividing said hollow interior into two chambers, said diaphragm being forced in a direction, by the biasing of the one valve, such that one chamber is enlarged;

a venturi in said water circuit; and

means connecting said one chamber to said venturi.

4. A hot water heating system as set forth in claim 1, wherein said one valve is normally biased in the closing direction of that valve and said fluid pressure responsive diaphragm-actuating means comprises:

a casing having a hollow interior;

a resilient diaphragm dividing said hollow interior into two chambers, said diaphragm being forced in a direction, by the biasing of the one valve, such that one chamber is enlarged;

a venturi in said water circuit; and

means connecting said one chamber to said venturi. 

1. A hot water heating system including: a water circuit having a heat exchanger, a radiator and a circulation pump; a gas burner for supplying heat to said heat exchanger, said burner including a gas supply device having a fitting defining an L-shaped gas passage with a first gas valve in one branch of said passage and a second gas valve in the second branch of said passage, each valve including respective operating rods with the rods being positioned in a cruciform pattern relative to each other, fluid pressure responsive diaphragm-actuating means bearing directly on one rod for actuating one valve and operatively connected to said water circuit to be responsive to the operation of the pump, and electromagnet means operatively associated with the other rod for actuating the other valve to the open position; an electrical control device having a thermostat and a first switch, said thermostat being positioned to be responsive to the temperature of the water in said circuit to actuate said switch in response to excess temperature; flame-sensing means having a second switch and positioned to actuate said second switch depending upon the presence and absence of a flame at said burner; electrical circuit means for said pump and said electromagnet means, said electrical circuit means including said first and second switches, said first switch being connected to deenergize said pump upon excess temperature in said water circuit and said second switch being connected to deenergize said electromagnet means upon the burner going out for allowing said other valve to then close.
 2. A hot water heating system as set forth in claim 1, wherein said two branches of said passage are at right angles to each other and the two valves are at right angles to each other, and the push rods are at right angles to their respective valves.
 3. A hot water heating system as set forth in claim 2, wherein said one valve is normally biased in the closing direction of that valve and said fluid pressure responsive diaphragm-actuating means comprises: a casing having a hollow interior; a resilient diaphragm dividing said hollow interior into two chambers, said diaphragm being forced in a direction, by the biasing of the one valve, such that one chamber is enlarged; a venturi in said water circuit; and means connecting said one chamber to said venturi.
 4. A hot water heating system as set forth in claim 1, wherein said one valve is normally biased in the closing direction of that valve and said fluid pressure responsive diaphragm-actuating means comprises: a casing having a hollow interior; a resilient diaphragm dividing said hollow interior into two chambers, said diaphragm being forced in a direction, by the biasing of the one valve, such that one chamber is enlarged; a venturi in said water circuit; and means connecting said one chamber to said venturi. 